Weight control, hoisting and drilling apparatus



l Sept` 3, 1957 c. M. oLEARY WEIGHT CONTROL 5 Sheets-Sheet 1 Original Filed June 50 l I I I 'In I I I I I l I I I l I I l I I I l I IIJ. I I I I l I I I I |I|I INVENToR,

raeA/Ef/ Aoriginal Filed June 3o, 1945 Sept 3, 1957 c. M. o'Ll-:ARY 2,805,042

WEIGHT CONTROL, HoIsTING AND DRILLING FAPPARATUS 5 Sheets-Sheet 2 Sept 3, 1957 c. M. O'LEARY 2,805,042

WEIGHT CONTROL. HOISTING AND DRILLING APPARATUS Original Filed June 30, 1945 INVENToR 02E/deff prroeA/Ef/ 4Sept 3, 1957 WEIGHT CONTROL. HoIsTING AND DRILLING APPARATUS IGGh-r- Aoriginal Filed June 50,1945

C. M. O'LEARY 5 Sheets-Sheet 4 speso' m ENG/NE S0650 agree reuenraee ISI JNVENTOR,

Sept 3, 1957 c. M.. O'LEARY 2,805,042

y wE1GHT coNTRoL. HoIsTING AND DRILLING APPARATUS riginal Filed June so, 1945 5 sheets-sheet 5 ENG/NE' 510560 United States Patent C WEIGHT CQNTROL, HoIsrINe- AND DRLLLING APPARATUS.

Charles M. OLeary, LosAngeles, Calif.

Continuation 0E abandoned applicati-ou Serial` No. 602,619, .lune 30,4 1245,., Thisfappiication Marcil 19 1952, SerialNo. 27,7;456 n 3 Claims. (Cl'. 2 55-19).

My present invention is. a continuation of my application` Serial No. 602,6;19 for Oil Well Drilling Apparatus, filed lune 30, 19.45, andnow abandoned.

The present invention relates to weight control, hoisting and drilling apparatus and particularly to. the mechanism for driving and controlling the mot-ion of the hoisting and weight control drum.

In deep oil' well drilling a very large portion of the total drilling time and, therefore, of' the cost ofv the.

operation iis/spent in pulling the drilling stem from the well: to renew the drilling bit and then returning the stem and bit to drilling position. In View of the heavy weights involved on the hoisting drum very. large amounts of power and great llexibility oli controli aire required to pull the drill stem from the well as rapidly as possible in order to reduce the, waste time.V In addition, very heavy duty the use of a combination of one or more internal'combustion engines connected to the hoisting drum through a hydrokinetic torque converter. Suciha combination provides an exceedingly high starting torque which is required, and a desirable automatic decrease in torque ratio as the speed of the drum increases during hoisting operations. However, the eciency of the hydrokinetic torque converters is very low, except at a fixed speed ratio, and in the prior mechanisms it has not been possible to maintain the torque ratio on a converteriat or near the point of maximum efficiency during any appreciable portion of the hoisting operation. As a result, the torque converters have been subject to destructivewheat generation,

and it has not been possible to realize their full advantage.

ln addition, due to the heat generation in the torque converter, it has not been possible to operate with the output of the converter either stationary or operating at very low speeds for any appreciable period of time.

The expressions hydrokinetic torque converter or simply torque converter designate the familiar Fttinger torque converter shown in Figures 8 to 14, inclusive, in the United States patent of Fttinger No. 1,199,359 of September 26,` 1916'. The Fttinger patent also disclosed, in Figures l to 7, inclusive, a hydrokinetic coupler. Both hydrolcinetic couplers and hydrolcinetic torque converters transmit torque by imparting kinetic energy 'to a liquid and providing a drivenmernber in the -form of a hydraulic turbine to absorb the energy. Since both transmitftorque, by kinetic energy, the magnitude of the transmitted; torque for any given output speed is a function Of: thQ Input speed (i. e., the speed difference).- The tQrqueconverter diiers from the coupler in that it employs stationary re,- action vanes to. guide. the liquid and consequently multiice plies torque, whereas the coupler never delivers torque in excess of the input torque.

The above defects in prior torque converter operated drilling rigs are, to a large extent, overcome by the use of the apparatus disclosed in applicants copending application, Serial No. 571,656, now abandoned, wherein the torque converter is connected to the hoisting drum through an automatic two-speed transmission and a manually selectable ohange-speed transmission which will provide a plurality of diierent torque ratios in the drum drive. The automatic transmission is so arranged as. to decrease they torque multiplication ratio between the torque converter and the drum when the speed ratio of the converter exceeds the ratio of its efli'cient operating range. The decreased torque multiplication ratio thus provided automatically restores the converter to its minimum edicient speed' ratio. without changing the speed of or the torque applied to the hoisting drum. With the apparatus of sa-idcopending application it is possible for theA operator,

iin the exercise of his judgment, to preselect a speed ratiol in the manual transmission which will approximate that lrequired to hoist a stand or drill pipe, and. once the hoisting has started the automatic transmission will operate tok maintain the speed ratio of the converter in its eflicient range provided' the proper speed ratio in the manual trans, mission was properly selected. However, there is a substaintial range in torque on the hoisting drum from the high starting torque to the minimum torque during the hoisting of each stand of drill stem, and, consequently, if the speed ratio of themanual transmission is not proper`- ly selected the torque aange [available within the elilicient` speed ratio,- range of the torque converter may not be suicient, in whichv event the torque converter will Operate in part in ian inefficient range. Moreover, the operatory has no way of knowing whether the torque converter is operating at ain etiioient speed ratio or not, and, conse-K quently, may continue to operate the apparatus under ineoient conditions.

It is one object of the present invention to improve upon the characteristics of the apparatus disclosed in said; copending application by providing means; for adjusting the torque ratio of the hoisting druml drive during the hoisting operation without danger of dropping; the load.`

Another Objectis to provide an indicating means for indicating to the operator when a speed, ratio change` is required and in what direction it must be made.

Another objectof the present invention .is toprovide an improved and simplified apparatus for maintaining the pressure ofthe drill bit upon the formation at any desired constant value during the drilling operation.

Another object Kof the present invention is to provide aPPratus of the type mentioned which is capable of controlling the lowering of the drill stem into the Well` Y without the use of the usual. manual or hydraulic brakes previously employed.

Another object of the present invention is to provide an improved form of change-speed transmission which will provide a plurality of torque ratios which may be instantly selected by the operator under load without any release of :the torque load on the transmission and which is characterized by its ruggedness and simplicity.

Another object of the present invention is to provide a complete drilling apparatus including a plurality of engines which are connectable to the hoisting drum to hoist the drill stem from the well, which engines and drive conn ections are so arranged that during drilling operations one of the engines may be employed to control the weight of the drill bit on the formatiom while the remaining engines, may be used toY drive the .slush pumps and rotary table Another object of the present invention is ito provide improved and simplified means for controlling the shifting of a compounded change-speed transmission under load.

Other objects and advantages will become apparent from the foilowing specifications, the accompanying drawings, and the appended claims:

In the drawings,

Figure l is a more or less diagrammatic plan View of the complete drilling merchanism excluding only the rig and sheaves which are connected in the usual manner by a cable to the hoisting drum;

Figure 2 is an enlarged elevation view partly in section showing differential cooling mechanism for one of the torque converters.

Figure 3 is a longitudinal section taken through the combined automatic and manually controlled changespeed transmission shown in Figure l.

Figure 4 is a further enlarged fragmentary longitudinal section of a portion of the transmission shown in Figure 3.

Figure 5 is a fragmentary section taken on the line 5-5 of Figure 4.

Figure 6 is a transverse section taken on the line 6-6 of Figure 4.

Figure 7 is a perspective view of the control and indieating panel utilized to control the operation of the apparatus.

Figure 8 is an end view of the mechanism shown in Figure 7 with parts broken away to show the interior construction.

Figure 9 is a fragmentary section taken on the line 9 9 of Figure 8, with the parts in a different position.

Figures 10, 1l and 12 are sectional views of the valve operating cams taken on the lines 10-10, 11-11 and 12-12 in Figure 9.

Figure 13 is a graph showing the torque characteristics of the engine and torque converter employed in the preferred form of :the invention.

Referring to Figure l, the complete apparatus includes a rotary table 1, a hoisting drum 2, and slush pumps 3, of conventional construction. It will be understood that the drum is connected :to the hoisting sheaves of the drilling rig in the usual manner by means of a cable 4, which is wound on the drum. The drum 2 is adapted to be rotated by a sprocket 5 connected in the usual manner by a clutch 6 to the drum shaft and which is driven by means of chains 7 from a sprocket Sa on the output shaft 8 of a change-speed transmission 9. The input shaft 10 ofthe transmission has a sprocket 10a which is connected by a chain 11 to a sprocket fixed to a shaft 12. The shaft constitutes the output shaft of a hydrokinetic torque converter 13, the input shaft 14 of which is connected to an internal combustion engine 15. The shaft 12 also carries a double sprocket 16 adapted to carry chains 17 and 18. The double sprocket 16 normally runs freely on the shaft 12 but may be fixed thereto by energization of a pneumatic clutch, indicated diagrammatically at 19. Chain 1'7 runs over a sprocket 20 fixed on shaft 21 which is the output shaft of a second torque converter 22 connected to a second engine 23. The shaft 21 is also connected by a chain 24 and suitable sprockets fixed on shafts 21 and 25 to a shaft 25 which constitutes the output shaft to a third hydrokinetic torque converter 26, the input of which is connected to a third engine 27. Shaft 25 is connected to a countershaft 29 by means of a chain 28 and suitable sprockets fixed to shaft 25 and countershaft 29, and the latter carries a pair of sprockets 30 and 31. rfhe sprockets 30 and 31 normally run freely on the shaft 29 but may be fixed thereto by actuating either one or both of a pair of pneumatic clutches indicated diagrammatically at 32 and 33. The sprockets 3@ and 31 carry chains 34 and 35, respectively, which drive the slush pumps 3.

The previously mentioned chain 18 on the double sprocket 16 is `connected to `a sprocket 36 on an input shaft 37 of a table transmission 38. The sprocket 36 Lil normally runs freely on the input shaft 37 but may be clutched thereto by energizing a pneumatic clutch 39. The output shaft 40 of the transmission 38 is connected by means of a chain 41 to the rotary table in the usual manner.

As a result of the above connections, during hoisting operations, all three of the engines 15, 23, and 27 may be connected to the hoisting drum by energizing clutch 19 and deenergizing clutch 39. At this time the slush pumps may be disconnected by tie-energizing the clutches 32 and 33, thus making available the full power of all three engines for hoisting. During drilling operations, the clutch 19 may be de-energized and one or both of the clutches 32 and 33 energized. In that case, engines 23 and 27 will drive the rotary table 1 and one or both of the slush pumps 3 while the engine 15 will remain connected, through the transmission 9, to the hoisting drum. The engine compounding features of this application are claimed in applicants copending application, Serial No. 676,450, filed June 13, 1946, now Patent No. 2,589,121, issued March 11, 1952.

As best shown in Figures l and 2, each of the hydrekinetic torque converters 13, 22 and 26 is provided with a differential cooling mechanism indicated generally at u 42. This mechanism is preferably constructed in the manner set forth in greater detail in applicants copending application, Serial No. 240,178 filed August 3, 1951, now Patent 2,714,804 or the similar mechanism described in applicants copending application Serial No. 571,656, filed January 6, 1945, now abandoned, and disclosed and claimed in applicants copending application, Serial No. 666,626, filed May 2, 1946, now Patent No. 2,589,120, issued March 1l, 1952. Briey stated, the mechanism includes a cooling radiator 43, suitable con duits 44 and 45 for circulating the operating liquid of the converter through the radiator, and an air circulating fan 46 which is diffentially driven from the input shaft 14 and the output shaft 12 of the converter by a differential mechanism 47 and a pair of chains 48 and 49. The chain 48 is trained over a suitable sprocket on the output shaft 12 of the converter and about a sprocket 50 associated with the differential mechanism. The chain 49 is similarly trained over a suitable sprocket on the input shaft of the torque converter and over a sprocket 51 associated with the differential mechanism.

As best shown in Figure 2, the differential mechanism comprises a casing 52 which journals and supports a shaft 53 which carries the sprocket 50, and a second shaft 54 which carries the sprocket 51. The shaft 53 is provided with a spur gear 55, and the shaft 54 is provided with a larger spur gear 56. A plurality of planetary gear clusters co-operate with the gears 55 and 56, and one of such clusters appears in Figure 2. As there shown, each planetary cluster includes a spur gear 57 and a spur gear 58, the two being integrally connected together and journalled in a cage 59. The cage in turn is journalcd for rotation about the axis of shafts 53 and 54 by suitable bearings on the casing 52 and also provides a bearing support for the inner ends of the shafts 53 and 54. Formed integrally on the planetary cage 59 is a bevel ring gear 60 which meshes with a bevel gear 61 on a vertically extending shaft 62 which is journaled in a projecting portion 63 of the casing 52. The upper end of the projecting portion 63 of the casing rotatably supports a fan shaft 64 for the fan 46, and the sha ts 62 and 64 are connected by means of bevel gears 65 and 66.

It will be noted that when the planetary cage 59 is held stationary and either the shaft 53 or the shaft 54 rotated, that the shaft 53 will rotate at a higher speed than the shaft 54, due to the difference in sizes between the inter meshing sets of gears. The relative sizes of the gears are so selected that the ratio of speeds between the shaft 53 and the shaft 54, when the planetary cage 59 is stationary, is equal to the speed ratio of the torque converter when operating at its maximum efficiency. ln the usual case the speed ratio of the output of the torque converter to the input at maximum efficiency is between fourtenths and ve tenths. Consequently, the relative sizes of the gears 55 through 58 will be selected to provide a corresponding ratio between the shafts 53 and 54. As a result of this arrangement, when the torque converter is operating at maximum eciency the cage 59 and, therefore, the fan 46 will be stationary. However, as the speed ratio of the converter departs from its ratio of maximum efficiency in either direction the fan will be rotated in one direction and the other at a speed approximately proportional to the extent to which the speed ratio of the converter departs from its ratio of maximum efficiency. Consequently, the cooling effect of the differential cooling mechanism 42 will be generally proportion to the amount of heat generated in the converter.

The remaining members 23 and 27 are equipped with similar cooling units 42 which need not be further described.

The interior construction of the transmission 9 is best shown in Figures 3, 4, 5, and 6. As there shown, the unit comprises an automatic planetary two-speed transmission 67 and three manually controlled two-speed planetary transmissions 68, 69 and 70, all of which are connected in series. All four of the transmissions 67, 68, 69 and 70 are identical in construction except for a difference in the speed ratios they provide, and the fact that transmission 67 is automatically operated while the remaining transmissions are manually controlled.

As best shown in Figure 4, the input shaft is journaled in suitable bearings 71 carried by the housing 72 of the transmission. This shaft is provided with a bored opening 73 through which lubricating oil may be supplied, and at its right-hand end is counterbored to receive ya tubular pilot extension 74 which is fixed to the output shaft 8 and extends entirely through the transmission. The right hand end of the input shaft 10 is provided with a gear 75 adapted to mesh with a plurality of planet gears 76, each of which has fixed thereto a smaller planet gear 77 which is in mesh with a gear 78 on a tubular shaft 79. Shaft 79 is supported in a suitable antifriction bearing 8.0 carried by a web 81 formed in the housing 72 and isV also supported upon the pilot extension 74 of the output shaft 8.

Each of the planet gear clusters 76 and 77 is journaled by means of antifriction bearings in a planet cage 82 which in turn is journaled on suitable antifriction bearings 83 and 84 carried by the shafts 10 and 79, respectively. As a result of this construction, clockwise rotation of the shaft 10 as viewed from the output end of the transf mission tends to rotate the planet cage 82 in counterclockwise direction. However, if such rotation of the cage is prevented, clockwiserotation of the shaft 10 will rotate shaft 79 in the same direction at reduced speed ratio. In order to prevent such counterclockwise rotation of the planet cage 82 there are provided a plurality of oneway clutch blocks 85 which are tted within openings 86 formed in the casing 72 and are held in position by means of cover plates 87. The three blocks 85 are spaced equally around the cage 82, as best shown in Figure 6. A spring 88 normally acts to wedge the blocks between the cover plate 87 and the cylindrical periphery of cage 82. Thus, the three blocks 85 act as a one-way clutch between the stationary casing and the cage S2, Operating to prevent counterclockwise rotation of the casing, as viewed in Figure 6, so that the transmission unit 67 will provide an increased torque multiplication.

When it is desired to operate at a one-to-one ratio' through the unit 67, it is only necessary to lock the planet gears against rotation about their own axis. This vis accomplished by means of a plurality of clutch cones 89, one of which is fixed to each of the planet gear sets, and a co-operating clutch plate 90 provided with four coned clutch rings 91, one for each cone clutch element 89. The clutch plate 90 is slidable axially on the shaft v10 and is also free to rotate with respect thereto. Whenthe clutch plate is shifted to the left, as viewed in Figure 4, the cone clutch elements 89 are gripped by the cone clutches'91 and held against rotation about their own axes. This provides a direct one-to-one drive between the gears 75 and 78. During this condition `the cage 82 rotates freely in a clock-wise direction, as viewed in Figure 6, at the same speed as the shafts 10 and 79.

Means are provided to shift the clutch plate 90 into clutching position when the shaft'10 reaches a predetermined speed. This means comprises an antifriction thrust bearing 92 between the clutch plate 90 and a hardened ring 93. The ring 93 in turn is adapted to be forced to the left, as viewed in Figure 4, by projection 94 on an arm 95'which is pivotally mounted upon a ring 96 surrounding the shaft 79 and fixed thereto. The extremity of the arm 95 carries a cylindrical weight 97 which tends to swing the arms outwardly with a force which is a function of the speed of the shaft 79. Two weighted arms 95 are provided, each having a weight 97, as best shown in Figures 4 and 5. At each end of each of the weights there is provided a hexagonal projection 98 adapted to fit a correspondingly shaped hexagonal recess in a spring bracket 99, as a result of which the spring brackets may be mounted on the ends of the weights in any desired angular position around the axes of the weights 97. The bracket is held in the desired adjusted position by means of a nut. Extending between the brackets on the weights are a pair of springs 100 which constantly act to hold the weights and therefore the arms inwardly against the action of centrifugal force. The tension of the springs may be adjusting the angular position of the spring brackets 99 with reference to the cylindrical weights 97. The strength of the springs is preferably such that the weights will not move outwardly until the speed of the shaft 1t) reaches a speed corresponding to the speed at which the torque converter is operating at its maximum efficient speed ratio, as more fully set forth in applicants aforementioned copending application, Serial No. 571,656, now abandoned. It is sufcient to state here simply that the centrifugal weights 97 and associated mechanism operate the clutch and thus shift the transmission element 67 into a condition of direct drive when the speed ratio of the torque converter reaches a desired maximum value. Any suitable means, such as springs, not shown, may be employed to effect disengagement of the clutches when weights 97 are retracted. Preferably, however, the angle of the cone clutches is sufficient to effect automatic release of the clutch when the weights are retracted, so that no release springs are necessary. The torque multiplication ratio of the transmission 67 when the clutch elements 91 are disengaged, is preferably in the order of two to one, with the result that engagement of the clutches 91 cuts the torque multiplication between the torque converter and the hoisting drum approximately in half. As a result if the clutches 91 are designed to engage when the speed ratio of the converter is twice the lower ratio at which the converter operates at the same efficiency for a given load on the hoisting drum when the clutches 91 are engaged the torque on the converter will be doubled and the speed ratio of the converter reduced to half that at which the engagement of clutches 91 occurred, without any change in the speed of output or the torque applied to the drum. This combination of a hydrokinetic torque converter and an automatic two-speed transmission is claimed in applicants copending application, Serial No. 647,677, filed February l5, 1946, now Patent No. 2,589,119.

Each of the remaining transmission units 687 69, and 70 is identical in construction and mode of operation to the above described transmission unit 67 except that they provide different torque multiplication ratios when the cone clutches are released and the cone clutches are controlled manually. As best shown in Figure 4, the preferred method 3f-operating the clutch plates of the manually controlled transmission units is by air pressure. Thus, as there shown, the clutch plate 101 for the transmission unit 68 is shifted to the right to etfect engagement of the cone clutches 102 by means of an annular movable cylinder element 103 which bears against an antifriction thrust bearing 104 to shift the clutch plate 101 to the right, as viewed in Figure 4. The annular cylinder element co-operates with an annular piston 105 which is supplied with operating fluid through a passageway 106 and a conduit 107. As a result, upon application of fluid under pressure to the conduit 107, the cone clutches 102 will be engaged and the transmission unit 68 locked in a one-to-one ratio. When the uid pressure is released the clutch plate 101 will disengage and the planetary cage 108 will be held against clockwise rotation by a plurality of one-way clutch blocks 109:1 similar in construction and mode of operation to the previously mentioned clutch block 85. Under these conditions transmission unit 68 will provide an increased torque multiplication between a gear 109 on the right hand extremity of shaft 79 and a gear 110 on the left-hand extremity of a tubular shaft 111 which extends over the pilot projection 74 on shaft 8 and which is journaled in antifriction ball bearings 112 carried by a web 113 of the casing 72.

lt will be understood that the shaft 11?` is connected by means of the transmission unit 69 to a fourth tubular shaft intermediate the transmission units 69 and 70, and that the fourth tubular shaft will be connected in the same manner between transmission unit 70 to the output shaft 8 of the transn issie Pi`he construction and mode of operation of the transmission units 69 and 70 being identical to that of the transmission unit 63 is not illustrated in detail and need not be further described except to note that the torque multiplication ratios provided by the transmission units 68, 69, and 70 differ from each other in such a manner that by selectively engaging or disengaging the operating clutches of one or more of the three units a total of eight ditferent speed ratios may be obtained. Moreover, these eight diterent speed ratios may each differ from each other successively by the same percentage. For example, if the sizes of the gears in the three transmissions are so chosen that transmission unit 68 gives a torque multiplication of 1.26, transmission unit 69 gives a torque multiplication ratio of 1.59, and transmission unit 7G gives a torque multiplication ratio of 2,50, then the three units of the transmission will provide the following eight torque ratios by energization of the clutches of the indicated units:

Clutches engaged in units Torque ratio:

68, 69 and 70.

lt will be noted that each of the torque ratios thus provided is approximately .26 percent greater than the preceding torque ratio. lt will be understood, however, that any desired torque ratios may be provided by suitably proportioning the gears of the transmission unit.

ln addition to the above, each of the above torque ratios is doubled by the automatic transmission 67 when the speed of the shaft '79 is below a predetermined value. Consequently, the automatic transmission provides higher starting torque ratios and automatically cuts those ratios in half when the snaft 79 reaches a predetermined speed.

Tl e cone clutches of the transmission units 67, 68, 69 and 70 may be self-releasing when the clutch applying force is relieved or, if desired, clutch release springs may be provided in the usual manner.

An important feature of the form of transmission, as illustrated and described above, resides in the fact that all of the gears of the transmission are constantly in mesh and a shift from one ratio to another is effected simply by engaging or disengaging the cone clutch elements. Consequently, there is no possibility of dropping the load incident to a shift from one gear ratio to another. Moreover, the cone clutch units which are engaged to etl"ct a direct connection are each subject to a torque loa which is less than one-fourth of the input torque. fact, with a unit designed to provide a two-to-one ratio when the cone clutches are disengaged, the torque applied to each of the cone clutches during direct drive is only about i8 percent of the total input output torque of the unit. When the cone clutches are relea ed to in crease the torque ratio, the planet cages immediately slow down but are prevented from rotating reversely by the one-way clutch blocks S5, E09, ete., with the result that the increased torque multiplication becomes effective without any cessation in the drive impulse to the drum. The one-way clutch blocks themselves, being located a substantial distance from the center of rotation, are subject to relatively low holding forces for a given delivered torque.

A further feature of the transmission resides iu the fact that the tooth loading between the gears being distributed between the four sets of planet gears is only oncfourth that of the corresponding transmission of conventional design. Moreover, what is more important, none of the torque loads transmitted through the transmission subject the shaft bearings to radial loads. Cons-2A quently, the bearings, such as bearings S3, 84, 6l, Si?, ctc., need only be large enough to maintain the shafts in alignment. The only bearings which are subject to radial loads are the bearings which support the planet gears, and these bearings are not only relatively closely coupled on the rigid planet gear clusters, but the torque load is distributed between the four sets of planet gears in each mission and is reduced by reason of location of the bearings at a substantial distance from the axis of the main transmission shaft. The clutch blocks S5, being equally spaced around the cage 82, also assist in keeping the shafts in alignment. Accordingly, the design is pc culiarly suited to the transmission of the very heavy torques required for oil well hoisting drums.

Another feature of the transmission which is of importance in well drilling operation resides in the fact that in the event of failure of the air pressure supply 'for operating the clutches, or of failure of the clutches thornselves the transmission automatically shifts into maximum torque multiplication. Consequently there is no danger of dropping a load on the hoisting drum. Ready access may be had to the one way clutch bloei/.s for inspection and replacement.

An important feature of the transmission 9 resides in the fact that it is constructed to a large extent from a plurality of identical parts, with a consequent saving in cost. All of the planetary cages such as the cages dfb and 108 and the similar cages in thc transmission units 69 and 70 are identical in construction. This is achieved by locating the axes of the planet cluster gears in each of the transmissions on the same center lines. This can be done and a difference in torque multiplication ratio still provided by simply changing the relative sizes of the gears in the cluster. Likewise, the cone clutch units and the clutch plates of all four ol the transmission units are identical, the operating mechanisms .for the three transmission units 68, 69 and 70 are likewise identical and the one-way clutch blocks of all four units are the same. As a result of this fact, there is prov.. ed at low cost a very rugged eight-speed transmission which can be shifted under full load and which also incorporates an automatic two-speed transmission.

Means are provided in the form of a single control lever for selectively actuating the clutches and the transmission units 68, 69, and 70 to produce the eight progressively increased multiplication ratios referred to above.

This means, as best shown in Figures 7 through 12, comprises a control box indicated generally at 114 having suitably mounted therein three three-Way control valves 115, 116, and 117 for controlling the operation of the iiuid operated clutches in the transmission units 68, 69, and 70 respectively. Likewise mounted within the control box is a camshaft 118 having cams 119, 120, and 121 adapted respectively to control the operating plungers 122, 123, and 124 of the Valves 115, 116, and 117, respectively. The camshaft is provided with a pinion 126 adapted to co-operate with a gear sector 127 fixed to a control shaft 128 having an operating handle 129. The operating handle projects through a slot 138 formed in an arcuate wall portion 131 of the control box 114. Along side of the slot are provided suitable indicia, such as the numbers one through eight, yrepresenting eight torque ratios available in the transmission.

The operating cylinders and pistons for the clutches in the `transmission units 68, 69 and 70 are preferably pneumatically operated, in which event the three control valves 1 15, 116 and 117 may be any desired or conventional form of three-way air valves. Thus valve 115 may be a three-way air valve having an inlet port 132 which may be connected to any suitable source of air under pressure, not shown, an outlet port 133, which is connected in any suitable manner to the conduit 107 for the air clutch operating piston and cylinder unit 183, 105, of transmission unit 68, and an exhaust port 134 which communicates with the atmosphere. The particular valve illustrated more or less diagrammatically is of the type in which the outlet port 133 is normally in com munication with the exhaust port 134, and communica tion is blocked between the ports 132 and 133. The trapped air pressure in port 132 acts to hold the valve operating plunger 122 in its downwardly projected position. When the valve operating plunger 122 is forced upwardly, as viewed in Figure 9, communication between ports 133 and 134 is closed, and communication between ports 132 and 133 is open, thus permitting air under pressure to flow to the operating cylinder 103 of the transmission unit 68. The remaining three-way valves 116 and 117 are similarly constructed and connected to the transmission units 69 and 70, respectively.

The valve operating cams and the mechanism for rotating them are so constructed that when the operating level 129 is swung from the upper end of slot 130 to the lower end of the slot the valve cams 119, 120 and 121 rotate through seven-eights of a revolution. Each cam has a different arrangement of peripheral lifting surfaces to effect operation of one or more of the respective plungers 122, 123, and 124 for the different positions of the camshaft. Thus Figures 9 to 12 show the position of the parts when the operating lever is opposite the indicia 8 alongu side the slot 138, in which all three of the plungers 122, 123, and 124 are in their lowermost positions, thus exhausting air from all three of the clutch operating cylinders and providing the maximum torque multiplication through transmission 9. Upon movement of the operating handle from the indicia 8 to the indicia 7 the camshaft will be rotated in a direction indicated by the arrows in Figures through 12 by one-eighth of a revolution, thus bringing the raised portion 135 on cam 119 into position in which the elevation of the plunger 122 of valve 115 is effected. It will be noted that on a corresponding movement of the cams 120 and 121 no change in the position of plungers 123 and 124 occurs. On the next increment of movement of the camshaft 118, plunger 122 will be lowered and plunger 123 will be elevated by the raised portion 136 on cam 120. No change will take place in the condition of valve 117. 7On the next increment of movement plungers 1,22` and 1.23 will be elevated by raised cam portions 137 and 138 on cams V119 and 12@ without any change in the condition of valve 117. On a further increment of movement plungers'122 and 123 will be released and plunger 124 willV be elevated by lthe raised portion 139 on cam 121, thus eliminating the torque 10 multiplication available in transmission unit 70 for the first time. On the next increment of movement plungers 122 and 124 will be elevated by the raised cam portions 140 and 141, and the plunger 123 will be released by cam 120. On the next increment of movement plunger 122 will be released by cam 119, and plungers 123 and 124 will be elevated by the raised portions 142 and 143 on cams 120 and 121 respectively. VOn the iinal movement of the camshaft all three of the plungers will be elevated by the raised portions 144, 145, and 146,. It will be noted that the sequence of operation of the three valves is such as to produce the eight successive speed ratios referred to above in the proper order.

It will be noted that, when it is necessary to release one valve plunger and elevate another to effect a ratio change,

`the releasing and elevating operations occur simultaneously and thus prevent the imposition of abnormal load conditions on any of the parts.` Each of the elevated portions of the cams 119, 129, and 121 is provided with a depression adapted to tit the rounded end of the cooperating valve plunger. Since the plungers are normally urged downwardly, as viewed in Figure 8, either by a spring or by the air pressure at port 13.2, or both, the recesses in the raised portions of the cams operate as detents to retain the shift lever 129 in any desired position of adjustment.

An important feature of the apparatus resides in the indicating device shown in Figures 7 and 8 for indicating the speed ratio and eiciency at which the torque converter is operating in order to guide the driller in selecting the proper speed ratios for transmission 9 by means of lever 129.

The efficiency indicator may comprise any suitable mechanism for indicating the speed ratio at which the converter is operating but, for convenience of the operator,

it is preferably calibrated in accordance with the eliiciency of the particular torque converter employed. The speed ratio at which the converter is operating may be measured by any form of differential mechanism either mechanically or-electrically responsive to the difference in speeds between the input and output shafts of the converter. However, a novel form of indicating means which is exceedingly simple in construction is illustrated in Figures 2, 7, and 8. As best shown in Figure 8, the indicating device indicated generally at 147, is in the form of a magnetic eddy current coupling comprising a driving element 148 and a driven element 149, the driving element being located entirely within a cup-shaped depression in the driven element but being entirely disconnected therefrom. The driving and driven elements ,are independently journaled in a suitable casing 150 by means of antifriction bearings. Thus, the driving element is supported upon a pair of ball bearings `151V and 152 and the driven element is supported upon a pair of ball bearings 153 and 154.

The driving element is preferably formed as a multipole permanent magnet and the driven element 149 is formed of an electrically conductive material, in accordance with the usual practice in constructing electromagnetic couplings. The driven element 148 is rotated by any suitable means at a speed in proportion to the difference in speeds between the input and output shafts of the converter. This is readily effected in the apparatus of the present invention by connecting the driven element 148 to the diierential mechanism in the cooling unit 42 by means of a speedometer cable, indicated generally at 155. The speedometer cable is constructed in the usual manner with a stationary tubular flexible housing 156 having one end iixed to the casing 150 of the indicator 147 and the other end connected to a suitable boss 157 formed on the housing for gears 65 and 66 of the fan drive, as best shown in Figure 2. The in ner rotating element 158 of the speedometer cable has one end connected to a projection 159 on the shaft 62 of the fan drive, as shown in Figure v2, while its other end is'xed to the shaft 160 11 which carries the driving element 143 of the indicating device.

As a result of the mechanism so far described it will be apparent that rotation of the driving element 148 of the indicating device in either direction will tend to eiect corresponding rotation of the driven element 11i-9, and that the rotating force transmitted between the elements 148 and 149 will be generally proportional to the difference between their speeds of rotation. A spiral spring 161 is provided to resiliently hold the driven element 149 in a neutral position and to resist rotational movement of the clement from the neutral position in either direction. One end of the spring 161 is fixed to the hub i6?, of the driven element 149, and the other end is fixed to a mounting screw 163 carried by the casing 150. The shaft 164- which carries the driven element 149 projects from the casing and supports an indicating pointer 165 which co--opcrates with airy suitable form of efliciency and/or speed ratio indicating dial.

The preferred form of dial, indicated at 156 and in Figure 7, comprises a semicircular line along which the pointer is adapted to move. The strength of the magnetic coupler and the strength of the spring 161, are so selected that the pointer will remain in a vertical position so long as the driving element 148 is stationary and will assume a position rotated 90 from the vertical in a counterclockwise direction, as viewed in Figure 7, when the output shaft of the converter is stationary and the input shaft is operating at the normal operating speed of the engine during hoisting. As a result of this arrangement, the pointer assumes its Vertical position when the driving element 148 is stationary and thus, in that position. indicates that the torque converter is operating at maximum efficiency. Accordingly, as the speed ratio of the converter increases beyond that of maximum eflicicncy, the pointer will swing in a clockwise direction through an angle of 90 when the Spee ratio of the converter approximately double that of maximum eiiiciency. The particular form of dial illustrated is adapted for use in connection with a torque converter which reaches maximum efficiency at a speed ratio of .4 and, consequently, the right-hand extremity of the arcuate line represents a speed ratio of .8. From the known eiciency curve of the converter employed, the actual efficiency of the converter corresponding to a plurality of positions of the pointer along tlie arcuate line, may be determined and marked on the dial in the manner indicated in Figure 7. Likewise the corresponding speed ratios may be indicated along the horizontal line below the arcuate line, as indicated. ln general, it is desirable to operate the converter within an efiiciency range of tive percent of its peak efficiency and, consequently, the dial is suitably marked at 1.67 to indicate the, soscalled, efficient range of the converter. lt will be noted that the efficient range of the articular converter' to which the dial applies, ranges from a speed ratio of .25 to a speed ratio of .5.

lt will be understood that the particular form of indicating device, disclosed in Fig. 8, which incorporates a double acting spring, is required when the differential drive mechanism is designed to have a zero rotative speed when the torque ratio of the converter is at maximum etiiciency. lf an ordinary differential drive is used, the speed of the third member of the differential will be proportional to the difference in speeds between the inarid output shafts. In that case a single cting spring may bc used on the pointer and the pointer Will i ssume its left-hand or Zero speed ratio position when the speed of the driving member of the indicator is maximum. An intermediate speed of the driving member will represent the speed ratio of maximum efficiency.

As a result of the above indicating device and the provision of manually shiftable transmission which can be shifted under load during hoisting operations, the driller is able to instantly adjust the speed ratios in the transmission as required to obtain the most effective drive connection to the hoisting drum. In this connection the automatic two-speed transmission greatly facilitates the operation of the unit and relieves the driller o tne necessity of making frequent speed ratio changes. Thus, for example, if the proper speed ratio has been elected in the transmission 9 for hoisting any given stand of drill pipe, the pointer 165 of the efficiency indicator will move from its extreme left-hand position, as viewed in Figure 7, at the begining of the hoisting operation when the starting torque is high, upwardly along the arcuate line in a clockwise direction. if the torque load falls off to such a point that the pointer reaches the maximum eiiicierit sped ratio of .5 the automatic two-sped transmission 67 will automatically shift into direct drive thereby returning the pointer to the minimum efficient speed ratio of .25. Thereafter further reductions in torque load may occur without taking the converter' out of its eflicient speed ratio range. lf the driller observes that after the shift of the automatic trar mission to direct drive, the pointer is swinging clockwise beyond the eicient range of the converter he may instantly shift the manually controlled transmission 9 to a lower torque multiplication ratio, or if the entire stand pipe is hoisted without a movement of the pointer 165 clockwise as far as the eiiicient speed ratio range, he may instantly shift the manually controlled transmission to a higher torque multiplication ratio. These shifts can be made during the hoisting operation, and, consequently, insure that the drill pipe will bc hoisted at the maximum possible speed and efficiency at all times.

it is also preferred, as indicated in Figure 7, to incorporate in the control box 114 all other necessary indicating devices commonly employed in drilling operations, such as meters for indicating oil pressure, engine speed, water temperature, air pressure etc. lt is particularly important in connection with apparatus of the presend invention to employ individual engine speed indieating devices because, due to the fact that three engines v-.rill be driving the hoisting drum during the hoisting operations through individual torque converters, the output speed of the three torque converters will be the same and, consequently, the torque delivered by each engine will be exactly the same at any given engine speed. Accordingly, so long as the three engines are operating at the same speed, the driller knows all three are taking their share of the load. in addition, so long as the driller maintains the engine speeds the same, either by adjusting the throttle positions or, if governors are employed, by adjusting the governor settings, thc etlicieucy indicator, when connected to any one of the engine-converter units, will automatically indicate the cfiiciency of all units, since all will have the same converter speed ratios.

The apparatus of the present invention eliminates the necessity of employing either mechanical brakes or hvdraulic braking mechanisms to control the movernsit of the drill stem on going into the hole, due to the fact that all necessary braking forces may be applied to the drir'i by the engines through the torque converters. is made possible in the apparatus of the present invention by reason of the differentially operated cooling fan which automatically increases the amount of cooling of the operating liquid of the converters in approximate accordance with the amount of heat generated, and thus avoids destructive overheating which would otherwise result. Accordingly, the operator may, by simply manipulating the engine throttle, exert any desired braking force on the drum to control the descent of the drill stem or bring it to a stop when it is moving downwardly. In this connection the transmission 9 may be shifted to provide a torque ratio at which the engine throttle control of the braking will be most effective,

As soon as the drill stern is lowered into the hole in position for drilling, it is only necessary for the operator to de-energize clutch 19 and energize clutch 39, Where* upon engines 23 and 27 will be ydisconnected from the hoisting drum and connected to the rotary table 1 in the manner previously' indicated. At the same time one or both of the slush pumps' may be connected to the engines 23 and 27 by energizing clutches 32 or 33.

The operator may then control the pressure of the drill bit upon the formation, by proper selection of the torque multiplication ratio in transmission 9 and by adjusting the setting of the throttle for engine 15. This provides an exceedingly accurate and sensitive means for maintaining the drill bit pressure at a constant value, independent of the speed at which the drill bit penetrates the formation, due to the fact that with the output of the torque converter 13 stationary, the torquedelivered to the converter by the engine at any given engine throttle setting will remain absolutely constant and, consequently, the torque delivered by the converter to the drum will also remain absolutely constant. Moreover, the value of the torque s'o transmitted may be adjusted through a very wide range by simply adjusting the throttle position and fixing the throttle in the desired position of adjustment, due to the fact that under output stall conditions the input torque absorbed by a torque converter is a direct function of the input speed.

The manner in which this result is accomplished is indicated in the torque speed curves of Figure 13, which shows a curve 170 representing the input torque absorbed by the converter at various input or engine speeds, with the output of the torque converter staionary and it also shows the torque-speed characteristic curves 171, 172 and 173 of the engine at three different throttle settings. Curve 171 thus represents the torque-speed curve of the engine, with a lixed wide-open throttle, and curves 172 and 173 show the torque-speed characteristic curves of the engine with two partially closed throttle settings. It will be Vobserved that with a wide open throttle, for example, the combination of the engine and torque converter will necessarily operate only at the input torque and speed represented by the intersection between the lines 170 and 171. Likewise, as the throttle is adjusted to partially closed position, represented by the curve 172,- the unit will operate at an input torque and speed represented by the point of intersection between the lines 170 and 172. If the throttle is further closed to the point at which the engine curve is represented by line 173, the speed and input torque will remain 'at the value indicated by the point of intersection between the lines 170 and 173. Thus, for any given setting of the engine throttle, the engine speed and the torque supplied by the converter to the engine will remain absolutely constant so long as the output of the converter remains stationary. Since the torque ratio of the converter remains constant the output torque will likewise remain constant.

During oil well drilling operations the rate at which the drill bit penetrates the formation varies widely, depending upon the character of the formation, the speed of rotation of the bit, its sharpness and other factors, but the maximum speed of penetration is still so slow that its effect upon the speed of rotation of Vthe hoisting drum, and, consequently, of the output of the torque converter 13, will have a negligible effect upon the torque delivered by the torque converter. Consequently, fluctuations in the rate of drill bit penetration will have negligible effect upon the pressure exerted by the drill' bit on the formation.

An important feature of the automatic weight control achieved by the above described mechanism resides in the fact that the drill stem balancing torque delivered to the drum is independent of the drum speed. Moreover, the present method and apparatus for controlling the pressure of the drill bit on the formation is free from the objectionable hunting characteristics found in prior mechanisms which have been suggested for the same purpose. While many different forms of Weight control mechanism have been proposed, they may all be said to fall within two basic classes. In the first class, means usually hydraulic, are provided for developing aforce or pressure proportional to the weight of the drillstem supported by the hoisting drum, and means responsive to any change in the force or pressure are provided to alter the speed orf the drum. In the second class, the drum is connected to a hydraulic pump that operates against a restriction to fluid flow which builds up' a resistance to balance the desired weight. In this second type, as the speed at which the drill stem moves deeper v'aries, the back pressure on the pump tends to vary, and therefore, somey pressure responsive means must be provided to vary the flow restriction in order to maintain a substantially constant pressure. As a result, both prior classes of mechanisms depend upon the development of a faulty condition in the operation of the drilling mechanism, and then after the faulty condition develops energize means to correct the fault. For this reason the priorV devices are inherently subject to hunting. The hunting tendency is further aggravated by the very substantial friction present in the hoisting mechanism.-

In contrast with the prior mechanisms, applicants apparatus applies a substantially constant torque to the drum which is of any desired value, determined by the adjustment of the engine throttle and the torque multi plication provided in the power transmission train. The balancing torque so supplied is almost entirely independent of the speed of the hoisting drum during drilling operations, and, consequently, the bit is free to make hole at its Vown pace and at a tixed pressure on `the formation. The very slight variations in drill bit pressure which result from variations in the drum speed are negligible and do not initiate the operation of any corrective mechanism. Consequently, they do not have any tendency to induce hunting. Incidentally, it will be noted that since the table is driven off a separate engine, the weight balancing engine will not be subject to speed variations incident to variations in table torque.

While the engine control has been referred to as a throttle control it will be understood that some primey movers have other types of controlling devices. For example, diesel and other fuel injection engines are controlled by an adjustment of the injection mechanism. In either case, when the control device is set to provide a uniform fuel supply per revolution the apparatus will balance a fixed weight on the drum. Electric motors may be employed in conjunction with a controller which establishes a different but fixed torque-speed curve for each setting.

If the weight balancing engine is also used to drive apparatus which has varying load requirements, such, for example, as the rotary table, it must be controlled by a' governor which will maintain the engine or motor at a constant speed. In that case means should be provided to adjust the speed setting.

In order to reduce the amount of power required to support any given weight of drill stem, it is desirable to provide a substantial torque multiplication in the drive connection between the output of the converter `13; and the drum. This may be a fixed torque multiplication in the chain and sprocket connections 7 and 11 but also includes the adjustable torque multiplication ratios avail.- able in the transmission 9. j In accordance with the preferred form of the invention the torque multiplication ratio provided between the converter and the drum is sufficient to achieve the desired balancing of the weight of the drill stem during drilling operations by the expenditure of an amount of power which is less than that necessary to hoist the same weight of stem at any practical speed. In actual practice the minimum practical speed for hoisting the drill stem is about sixty feet per minute and much higher speeds are preferred since hoisting time is lost time during the drilling operation. For balancing the drill stem a torque multiplication ratio between the converter and drum may be employed which will reduce the amount of power required for balancing the weight of the stem to a value which, if directly connected, would be insuicient to hoist the same stem at the rate of thirty feet per minute,

In actual practice, the torque ratios which are used during hoisting when three engines are connected, are adequate when connected to the single weight balancing engine to provide the desired magnitude and range of torque ratio for the complete drilling operation. For example, if a change-speed transmission having the ratios set forth above for the transmission 9 is used, and a xed torque multiplication of about 1.5 is incorporated in the sprocket and chain drive 7, the unit may be used for drilling operations to a depth of about 15,000 feet with three 250 H. P. engines which develop maximum power at about 1800 R. P. M. The three engines will provide high speed hoisting performance and one of the three engines, in combination with the change-speed transmission, will take care of all weight balance operations during drilling.

In any event, the various torque multiplication ratios provided in the transmission 9 should be preferably such as to augment the load balancing torque range which is available by simply adjusting the throttle position of the engine. In other words, when, during drilling operations, the engine throttle for any given torque multiplication ratio of transmission 9 has been progressively opened to balance the progressively increasing weights of the drill stern until the throttle is wide open, the transmission 9 should then provide a torque multiplication ratio which will permit balancing of at least the same, or greater, load at a minimum throttle position.

It is to be understood that although I have shown and described my weight control mechanism in connection with well drilling apparatus, my weight control mechanism may be used equally as well independent of a well drilling rig for controlling the weight or motion of any object.

While only one form of the invention has been illustrated and described in detail it will be understood that the various elements which malte up the complete apparatus may be varied widely in design and construction without departing from the spirit of the invention or the scope of the following claims. Applicants efficiency indicator and its combination with a multiple speed ratio transmission is claimed in applicants divisional application, Serial No. 657,959, tiled Iune 30, 1945, now Patent No. 2,558,193.

I claim:

l. A drill stem rotating and weight control mechanism for a rotary well drilling machine, comprising a hoisting drum for the drill stern, a rotating source of power, a torque transmitting coupling having input and output shafts connected respectively to the power source and the hoisting drum, said coupling being of the type in which the input shaft is free to rotate independently of the output shaft and in which the torque transmitted from the input to the output shaft increases progressively with increases in the difference between the speeds of the input and output shafts and vice versa, the torque transmitted to the drum by said coupling acting in a direction to support a part of the weight of the drill stem, means to adjustably tix the speed of the power source to continuously 1C- balance a fixed portion of the weight of the drill stem, said power source having a speed suliiciently high so that any variations in the speed of rotation in the drum incident to variations in the rate of drill bit penetration during drilling operations will have a negligible effect upon the value of the torque transmitted to the drum, a cooling system for the coupling mechanism including a radiator and associated fan and means for circulating liquid through the radiator, means for dierentially driv- 1 ing the fan from the power source and the hoisting drum to dissipate all of the heat generated in said coupling mechanism during sustained drilling operations, and means independent of said power source for rotating the drill stem simultaneously with the transmission of said drill stem supporting torque to the drum.

2. A drill stern rotating and weight control mechanism for a rotary well drilling machine comprising a hoisting drum, a rotating source of power, a hydrokinetic torque transmitting device connecting the source of power with i.' the drum, means for adjustably fixing the speed of rotation of the source of power at a value which will cause said device to transmit a Xed torque to the drum to balance a xed portion of the weight of the drill stem during drilling operations, means for cooling the operating liquid of the device including a radiator through which the operating liquid circulates and an associated fan, means for differentially driving the fan from the power source and the hoisting drum at a sufficient rate to maintain the device at a safe operating temperature during sustained drilling operations, and means independent of said power source for rotating the drill stem simultaneously with the transmission of said drill stem supporting torque to the drum.

3. A drill stem rotating and weight control mechanism for a rotary well drilling machine comprising, a hoisting drum, an internal combustion engine having a control device for controlling the fuel consumption rate per revolution, a hydrokinetic torque converter connecting the source of power with the drum, means for adjustably lining the said control device in a position which will cause said converter to transmit a xed torque to the drum to balance a lixed portion of the weight of the drill stem during drilling operations, means for cooling the operating liquid of the converter including a radiator through which the operating liquid circulates and an associated fan, means for differentially driving the fan from the power source and the hoisting drum at a sufiicient rate to maintain the converter at a safe operating temperature during sustained drilling operations, and means independent of said engine for rotating the drill stem simultaneously with the transmission of said drill stem supporting torque to the drum.

References Cited in the tile of this patent UNITED STATES PATENTS Re. 18,947 Greve Sept. l2, 1933 2,080,804 Brantly May 18, 1937 2,133,017 Brantly et al. Oct` 11, 1938 2,161,075 Morgan lune 6, 1939 2,185,498 Carson et al. Jan. 2, 1940 2,282,597 Archer May 12, 1942 2,332,310 Durham Oct. 19, 1943 2,351,654 Anderson June 20, 1944 

